Hoarder's Brain Works Differently

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Patients with hoarding disorder exhibit distinct cerebral abnormalities on functional MRI in the anterior cingulate cortex, and in the right and left insular cortex, when faced with making decisions about discarding trivial possessions.

Note that the activity in the anterior cingulate cortex and insula were hypoactive when the object in question belonged to someone else.

While making the decision to save or discard an item such as a piece of their own junk mail, those with hoarding disorder had significantly greater hemodynamic activity on fMRI in the anterior cingulate cortex (P=0.01) and in the right and left insular cortex (P<0.05) compared with both healthy controls and patients with obsessive compulsive disorder (OCD), according to David F. Tolin, PhD, of Yale University in New Haven, Conn., and colleagues.

In contrast, the activity in those areas of the brain were hypoactive when the object in question belonged to someone else, the researchers reported in the August Archives of General Psychiatry.

"Current models of hoarding disorder -- defined as the excessive acquisition of and inability to discard objects, resulting in debilitating clutter -- identify various deficits in cognitive processes, as well as maladaptive beliefs and behavioral patterns, as relevant underlying mechanisms," they explained.

Previous imaging studies have identified alterations in hemodynamic activity among patients with conditions such as hoarding and OCD, in various areas such as the prefrontal cortex and the parahippocampal gyrus.

Hoarding disorder was previously a subtype of OCD, but has been proposed as a unique diagnostic entity in DSM-5, the authors explained.

To more thoroughly examine the "neural mechanisms of impaired decision making that are specific to hoarding disorder," Tolin and colleagues enrolled 43 patients with that disorder, 31 with OCD, and 33 healthy controls.

Participants were asked to bring an assortment of papers from home such as newspapers and junk mail, and the investigators provided a similar collection for each participant.

The objects were scanned into a computer, and labeled "yours" or "ours."

Functional MRI was performed as patients were asked to decide whether each item could be shredded, and after the scans, patients were asked to rate their emotional feelings while making the decisions.

Patients with hoarding disorder discarded fewer of their own items (29) than OCD patients (37) or healthy controls (40), which was a significant difference (P<0.01), the researchers reported.

In contrast, there were no differences between the three groups when deciding to discard an item not their own.

Patients with hoarding disorder reported more anxiety, sadness, and indecisiveness, as well as feeling "not just right," (P<0.05) and each of these four emotions correlated with the number of personal items shredded:

Anxiety: r = −0.40

Sadness: r = −0.54

Indecisiveness: r = −0.35

"Not just right" feeling: r = −0.39

Controlling for depression and OCD did not significantly alter these findings.

When the emotions were compared with findings on fMRI, there were correlations between hoarding patients' anxiety and hemodynamic activity in the frontal gyrus, while feelings of indecisiveness correlated with activity in the frontal gyrus, insula, and uncus.

Their feelings of sadness were linked with increased activity in the frontal and temporal gyrus as well as the ventral striatum, while "not just right" emotions correlated with heightened activity across a range of areas including the frontal gyrus, anterior cingulate cortex, insula, and hippocampus.

The affected areas of the brain are associated with perceptions of uncertainty, unpleasant feelings, risk assessment, and emotional decision-making, the researchers noted.

The pattern of hypoactivity when hoarding patients were not faced with choices about their own possessions is a finding that has also been seen among patients with autism.

But the hyperactivity that resulted when the focus was on their own belongings is more typical of individuals with anxiety disorders.

"Hyperactivity in these regions may hamper the decision-making process by leading to a greater sense of outcome uncertainty, which would be consistent with the present correlations of subjective indecisiveness and 'not just right' feelings, contributing to a subjective sense that the wrong decision is being made," they explained.

The researchers noted that their study had certain limitations, including the likelihood of some subclinical OCD in hoarding patients, and vice versa.

In addition, the hoarding disorder group consisted predominantly of white women, so the generalizability could be questioned, particularly because the condition is thought to be more common among men.

The analysis also did not account for decision time, which may be an important component of the difficulties in decision-making among hoarders.

The study was funded by the National Institute of Mental Health.

The lead author has received research support from Endo Pharmaceuticals, Merck, and Eli Lilly. One co-author is involved in research funded by Medtronic and Cyberonics.

Reviewed by Robert Jasmer, MD Associate Clinical Professor of Medicine, University of California, San Francisco and Dorothy Caputo, MA, BSN, RN, Nurse Planner

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